700cc questions

After reading this thread about how a 700cc (with 65mm cranks) won the unlimited race, I have gained a lot of interest in the wheel size.

Can this wheel fit into a Nimbus frame (designed for a 24 - 26" wheel)?
If the rider that won rode a Coker, would he have won by more time?
Was Gizmoduck competing in this particular race?
What are the components of the wheel that won (rim, spokes, crank, hub tire)?
What was the average speed of the winning rider?

I am interested in riding somewhat short distances (<24 miles) at fast paces (12-14mph). I’d like to be able to keep up with the LOCAL Coker riders. They are not rockets or 600 mile riders like the superduper guys on this forum. The above speed and distance will be fine.

Ideally, I would love to simply change the wheel on my current setup, change the setting on the cyclometer, and “go” ride 10 miles in 45 minutes (13.3 mph).

I’m thinking that a 700cc will offer a wide range of tires, durability, cheap cost, compact size, ultra-light weight and unique handling that won’t be so “Coker-like.”

Perhaps I will never “eat Cokers” like the winner of the race, but if I can hold 12-14 mph for 20 miles, it would meet my desires.

Any insight?

Re: 700cc questions

Well, I’m 42 now, so a bit past my prime, but I keep fit, and only weigh 10 pounds more than I did at 21…

A couple of years back, I trained hard about 3-4 times a week on a Coker with 150s, and rode against the clock for an hour at a time. The best I ever managed was a distance of 12.95 miles in an hour. That was training hard, and taking it very seriously, and with a background in bicycling big distances.

On flat out 2 hour rides (that’s 2 hours with no dismounts at all) I managed just over 22 miles once, and over 20 miles a couple of times. That’s an average of 11 mph.

OK, so I’m no Lance Armstrong, but as a fit, experienced and determined rider, I was busting a gut to hit these figures, with lots of serious training.

12-14 mph for 20 miles on a unicycle would be very impressive - elite stuff. Not impossible, but beyond any but the most committed, talented, and determined. Good luck.

As for matching that on a 28/29 - do the maths and see the cadence you’d have to maintain. A big wheel will always be faster than a smaller one over a distance, other things being equal.

The 700c beat the Cokers on a 10km unlimited race. In this case, the smaller wheel won. Seems to me that 10km is a pretty long distance. Enough distance to give the Coker time to “sprint.”

The local guys pull an AVERAGE of 10mph. Duane told me that is their basic “crusing around” speed. I’m pretty sure AJ said he held 11mph average for the MS 150. Seems like your speeds are a bit slow (compared to those that don’t train as hard as you did).

The 700c wheel size is appealing to me. I’m curious to get the answers to the questions I listed above.

For one thing, imagine if Gizmoduck was participating in the race - we all know he holds a world record, trains hard, isn’t “too old,” and is probably one of the top 10 Coker riders of all time. If HE was outrun by a 700c it’s more “proof” that . . . well, a 700c wheel can win that race, and keep up with a Coker.

It would be nice to know what the average speed of the winning rider was. I’m thinking that Gizmoduck and others can stay about 12mph for 10km - and guessed that the winner had to be pulling 12-14mph for the entire distance.

I don’t think that many people ride a 700c. Well, not on this forum. I just don’t see a bunch of people beating on their chests about (like the other wheel sizes).

I like riding distances on the road that are 24 miles (and less) for various reasons. If I got a similar setup to the one that won the unlimited race, could I
a. keep up with Cokers for 20 miles (not 12mph average or less).
b. integrate the 700c wheel into my current setup

I see on unicycle.com, that they sell a

“Semcycle XL 700c (28- or 29-inch) with Kovachi Wheel”

Is there no difference between a 700c and 28"?
The reason I ask is because Foss implied a difference in the thread that I linked to above.

Is it possible to buy a KH29 and then occassionally replace the wheel with the “racing 700c”?

It is the same rim diameter whether it is called 700c, 28" or 29" namely 622 mm

the kh 29 rim is quite wide (38mm according to unicycle.com ) A normal slick 700c racing tyre might not fill that sort of width very well, even though the rim is the same diameter.


yes - i think. 700c refers the rim. 28" and 29 inch refers to the tires.

10 km roughly equals 5.9 miles = less than half an hour at the speeds we’re talking about.


They do - they just call them 28s or 29s, depending on the tyre size. I have a Coker and a 28 (and other unis) and have ridden fair distances on both, on and off road. I’ve also done speed comparisons on a variety of wheel sizes and crank sizes. It’s a long time ago, now, but the gist of the results was that, given approximately equal crank:wheel ratios, the larger wheel will generally be faster over a distance. Within “reasonable limits” (a deliberately subjective term) the smaller crank:wheel ratio will generate a higher top speed - but ultimately, the reduced control lowers journey speeds.

Consensus in this forum seems to be that 29s are faster than 28s because of the rolling momentum that helps to iron out minor bumps etc.

What happens when a specialist trains on a specific set up over a long period of time may be a different thing.

On my training these past months on a 28.5 tire (700c rim) with 150mm cranks in hilly terrain I typically average 10.3 km/hour. I’m not racing, nor do I try to ride fast, it’s just that after a while you’ve got places to go. When riding with other people I ride faster. I have the cyclometer on auto so it shuts off after a bit during breaks. My max seemed to be about 14.2 kph or so. It would seem quite reasonable to shorten the cranks quite a bit for flatter terrain and bump up my average (after practice) to 10 mph or more. For a young, fit, handsome guy like you, I’m sure that 12mph wouldn’t be unreasonable. :stuck_out_tongue:

John Stone, in his 30s, regularly rides his 29er at about twice my speed, using 110s, I believe.

I’m starting to “get a clue” about this 700c thing.

I talked to unicycle.com and they have a smaller NAUCC wheel that will fit in my current frame. Not sure what the exact rim size is (the guy guessed 26").

Perhaps I could get the smaller wheel, and then use the 65mm cranks.

I’m guessing it would be “best” to get a KH 29" and then buy the extra 700c wheel for road racing. (Looking for utility here). That way the new frame could double for cross-country.

I could just stick with the setup that I have. I’m not a good rider. The setup that I have is the most “useful” for me. I have to admit that sometimes I wish I could go a little farther and faster with the effort that I put out.

I’m not young. :frowning: Well, at least not my body. (32)
Wow, I wonder how much John trained.

It sounds like (with my obsessive mindset) I could get to 12mph (using 65mm cranks and 700c wheel). The next question is could I do it on the wheel that would fit my current frame?

I don’t mind working harder than the Coker riders. I want to be able to ride with them and NOT have to get a Coker. Perhaps a fixy bike (geared the same as a Coker, with forward and reverse pedaling like the bike messengers use) would be the solution. Nah. I don’t want that either.

  1. I’d like to know which rim to get (to fit a Nimbus frame AND withstand my weight).
  2. I’d like to know what cranks and hub to get (to fit a Nimbus frame AND withstand my weight) and be 65mm.

For ChangingLINKS:
Yes, it’s not cubic centimeters. Actually I don’t know what the sincle “c” stands for. 700 is not millimeters either BTW. It’s just a rim size with a kind of annoying name.

Gizmoduck came in 4th in the 10k at Unicon XII. I believe he led almost the entire race, then got kind of screwed because he missed a non-marked turn near the end. Racing results are here (you get to do the math on the finishing times):
It’s on page 35 in the giant PDF.

Please note that this 10k course was on a riverside bike path. In other words, WAY FLAT! There were hills at the turnaround points, where the path took a long slope up onto a dike. Maybe 20m rise in 150m or so.

All other things being equal, the larger wheel will probably previal in a more “typical” riding environment. Austin may be very flat also, which would be in your favor. The advantage to messing with a 700c unicycle is that it’s smaller, easier to store/transport, etc. Also you have hundreds of tires to choose from. It’ll be a bumpy ride though, if you go with something like what Yuta was using.

Remember, with 65mm cranks, any size unicycle is going to suffer from near-zero leverage. You’ll die on hills, and may have trouble with bumps, crowded places, etc.

I’ll be curious to hear what you find out about average speeds on those race times. It’s a standing start, but I’d just assume a constant speed for the whole time.

Yuta crossing the finish line (looks like a Miyata deluxe frame):

The mountain biking community is apparently aware of this as well. Yesterday we were in Downieville, and it’s one week before their big race there. A guy came up to us and commented on how his friends love the KH 29er rim for mountain bikes!

I understand the measurement is not “cc” or “c.”
I was drunk when I wrote the original post and thoughtlessly corrected it to “c” rather than “cm.”

Here are the times:
Yuta Ando 23:33
Roger Davies 23:36
Daiki 25:00
Ken Looi (The GizmoDuck) 25:16
Hajime 25:47
Nathan Hoover 26:42

I know that:
10km is 6.21 mi

I know that:
10 miles / 5mph = 2 hours
10 miles / 2 = 5mph

I’m not a math major, and got somewhat confused, but I think Yuta was going at 16mph.
10 miles/(23.33 time/60 minutes) = 10 / .3888 = 25.72 km/hr
25.72 * .62 (convert km to mi) = 15.94 (or about 16mph)

Nathan would be pulling about 14mph.
My guess is that Nathan was on a Coker.

What was Roger Davies riding?

missed the edit.
I saw Davies on a Coker
and calculated that Foss was doing about 13.6mph (using his 28).

Seems like there was not a radical difference in speed due to wheel size especially considering the experience of the riders involved.

A little ambiguous - do you mean the speed of 12 mph, or the distance of 12 miles covered in an actual hour?

12 mph as a speed is fairly easily achievable on a 700c. From memory, when I used to record such things, I think I logged a max speed of 16 or 17 mph on a Coker/150, and about 13 or 14 mph on a 28/110.

Maintaining the speed for a whole hour (or longer) is the problem.

Take a 700c with a fat tyre - call it a 29 inch rolling diameter.
Circumference = Pi x 29 = 91 inches covered per revolution.

A mile is 1760 x 36 = 63,360 inches

A mile is therefore 63,360 / 91 = 696 revolutions.

1 mile per hour = 696/60 = 11.6 rpm.
12 mph = 11.6 x 12 = 139 rpm.

Not impossible, but requiring not only a high level of fitness, but also a very high level of skill and concentration, even in ideal circumstances: flat surface, no headwind, no traffic, no junctions…

Something to keep in mind when comparing the 10K race times at Unicon and NAUCC is that many people do not bring their Coker to those events. The Coker is difficult to take on a plane and when you also want to bring along your 20" freestyle, your muni, your 24" track uni, your trials uni and other gear, well, the Coker just gets left behind. A 29er with short cranks is easier and lighter to pack up for a plane flight so some people are probably opting to take a 29er with short cranks instead of their Coker even if they can ride faster on the Coker.

Roger, Ken and Nathan were all on Cokers.

I was riding a nominal 29" Schwalbe Big Apple tire with 102mm cranks. I was trying to keep up with my little group of kids on 24" wheels with teenytiny cranks.

Me with my group:

Nathan with his group (they were ahead of me):

I have done a 9-mile race at around 11mph on a 24" wheel with 125mm cranks. I used to be able to max out at 17.5 mph, but only very briefly.

It’s not that hard to keep up with Coker riders if you’re on a 29". I’ve done it on my 29" with 125mm cranks and I’m no athlete. You’ll be spinning faster when they’re ‘cruising’ but it sounds like that’s what you want anyways. OTOH if they’re hammering it I think it’d be a lot harder to keep up.

  1. Though Cokers were not easy to travel with, the people who had Cokers were “stellar” riders. I’m thinking the race would shake out the same had there been more Cokers.

  2. Portability and durability are 2 reasons that I am seriously considering this wheel size.

I don’t have to be able to “win” anything. Perhaps I could never race Cokers . . . .however, it would be nice to be able to keep up - or even beat a weak Coker rider.

I think I am more interested in the 24" setup that John Foss was competing with. I really want to be able to use my current setup (so that I can simply change the wheel and “go”).

That way, I could buy a 20" trials wheelset, keep my 24" and have something ABLE to keep up with Cokers - all by changing the wheel.

Sort of a threadjack: I was riding my 20" unicycle and i put a speedometer/odometer on it and i tried to see how fast i could ride. I reached 14.2 mph for about a second or so. Does this seem accurate or is my speedometer wrong?

I rode the 20" on a 3 mile loop when my dad clocked it in the car (i wasnt with him so i dont know it was exactly 3 but that is what he said), and it said i went 3.75 miles. Is it because my wheel swirves back in forth sometimes or is it just wrong?